Conventional apparatuses for driving an icemaker of a refrigerator have been suggested as disclosed in the publications of, for example, the patent document 1 and the patent document 2.
As shown in FIGS. 1 to 2, a conventional apparatus for driving an icemaker of a refrigerator includes a driving motor 10; a cam assembly 30 which is disposed to be interlocked with an ejector E for ejecting the ice cubes made in an ice-making tray, to an ice bank; an ice-detecting arm 50 which detects the ice-full state of the ice cubes ejected to the ice bank as it is rotated by the cam assembly 30; a gear unit 40 which is interposed between the cam assembly 30 and the ice-detecting arm 50; an ice-full state sensing unit which senses the ice-full state of the ice bank by sensing the position of the cam assembly 30 when the cam assembly 30 is operated in the interlocked manner; and an ice-detecting arm sensing unit which senses whether or not the ice-detecting arm 50 has not returned to an initial position by being interfered with by the ice cubes present in the ice bank.
The cam assembly 30 includes a driving cam 31 which is transferred with the rotation force of the driving motor 10 using a motor or the like and is rotated along with the ejector E; and an ice-detecting lever 33 which is rotated by the driving cam 31 and of which rotation position is to be sensed by the ice-full state sensing unit.
The ice-detecting lever 33 is projectedly formed with a cam follower 34 which contacts a cam surface 31a of the driving cam 31. Also, a first extension 33a and a second extension 33b are formed on the ice-detecting lever 33 substantially opposite to the driving cam 31. Teeth 33b′ are formed on the distal end of the second extension 33b. 
The gear unit 40 is constructed by a first gear 41 which is meshed with the teeth 33b′, a second gear 43 which is coupled to the same rotation shaft 42 as the first gear 41, and a third gear 45 which is meshed with the second gear 43.
A holder 47 is coupled to the third gear 45, and the ice-detecting arm 50 is held on the same rotation shaft 46 as the holder 47.
A torsion spring 49 is disposed between and coupled to the third gear 45 and the holder 47.
Therefore, even when an external force is applied to the ice-detecting arm 50 in a reverse direction, the reverse rotation thereof is substantially suppressed as the torsion spring 49 is elastically deformed, and thus, the forcible rotation of the third gear 45 connected to the ice-detecting lever 33 does not occur. Since the detailed description of the torsion spring 49 is concretely given in the patent document 1, it will be omitted herein.
In the conventional apparatus for driving an icemaker of a refrigerator, constructed as mentioned above, when ejecting ice cubes by using the ejector E, the ejector E scoops ice cubes while rotating in an ice-ejecting direction (the direction I), that is, an ice-discharging direction (hereinafter, referred to as a normal direction), and pushes the ice cubes to the left side when viewed on the drawing.
In order for the above-described ice-full state sensing unit to sense the ice-full state, the ice-detecting arm 50 is rotated while the ejector E is rotated in the normal direction as stated above. In this case, while the ejector E is rotated in the normal direction, the ejector E may be interfered with by the ice cubes present in the icemaker.
In other words, despite that the ice-full state should be sensed by the ice-detecting arm 50, in the case where the ejector E is interfered with by the ice cubes present in the icemaker as described above, a problem may be caused in that determination may be made to the ice-full state even though it is not the ice-full state and thus making of ice cubes may be stopped.
Meanwhile, the rotation angle ratio of the second gear 43 and the third gear 45 is 1:2. Accordingly, the displacement range of the torsion spring 49 is two times larger in the case where the torsion spring 49 is disposed between the third gear 45 and the holder 47 than in the case where the torsion spring 49 is disposed between the first gear 41 and the second gear 43.
Due to this fact, in the case where the torsion spring 49 is disposed between the third gear 45 and the holder 47, when compared to the case where the torsion spring 49 is disposed between the first gear 41 and the second gear 43, a maximum two times larger amount of torque is transferred to other components such as the ice-detecting lever 33. As a consequence, problems may be caused in that adverse influences are likely to be exerted on the components, for example, the durability of the components is likely to deteriorate or a precise rotation force is not likely to be provided.
A torsion spring 37 is disposed around the rotation center of the ice-detecting lever 33 to bias the cam follower 34 to elastically contact the cam surface 31a. The torsion spring 37 has a cylindrical coil part 37a which is installed by being fitted around the rotation center of the ice-detecting lever 33, a first arm 37b the distal end of which is supported by a first support pin 3 formed on a gear box 1 positioned adjacent to the first extension 33a, and a second arm 37c the distal end of which is supported by a second support pin 5 formed on the lower surface of the second extension 33b. 
The torsion spring 37 having such a layout is encountered with a problem as shown in FIG. 19.
Namely, it may be seen that, if the second arm 37c is bent from the position shown by the dotted line (the state shown in FIG. 1) to the position shown by the dotted line (the state shown in FIG. 2), the reaction force applied to the ice-detecting lever 33 by the second arm 37c satisfies the relationship of F1<<F2.
Also, it may be seen that the arm length r1 of the reaction force F1 is approximately equal to the arm length r2 of the reaction force F2.
Accordingly, because the moment satisfies the relationship of M1(F1×r1)<<M2(F2×r2), the moment may be changed from a minimum value to a maximum value according to the direction of the force applied to the ice-detecting lever 33. As a consequence, problems may be caused in that adverse influences are likely to be exerted on the components interlocked with the ice-detecting lever 33, for example, the durability of the components is likely to deteriorate or a precise rotation force is not likely to be provided.
Meanwhile, since the icemaker and the driving apparatus described above belong to widely known technologies and are described in detail in prior art patent documents, specifically, such as Korean Patent No. 0531290, Korean Unexamined Patent Publication No. 2007-0096552 and Korean Unexamined Patent Publication No. 2008-0035712, detailed description and illustration thereof will be omitted.